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IC 443 - the Jellyfish nebula in LRGB

Whippy

By Whippy
in Imaging - Deep Sky

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Whippy

Whippy

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An unexpectedly clear but windy night yesterday gave me the opportunity to grab some colour data for the Jellyfish nebula in Ha I did back in late November (see here: http://stargazerslounge.com/index.php/topic,34887.0.html) . Not entirely sure about the ZS66 imaging in colour (perhaps I shouldn't be binning the colour data?), and I did have some fairly nasty gradients to deal with but after a couple of attempts, here's an effort I'm pretty happy with. I've got the colour to get for my mono M81/81 so we'll what happens with that.

So, IC443. Total exposure time 5hrs 30 mins, Ha used as luminence 2hrs 50 (17 x 10 mins), Red and Green 48 mins each (12 x 4 mins) and Blue 1hour 4 mins (16x4 mins). Taken with an Atik 16HR camera with an Astronomik 13Nm Ha filter, IDAS LP and Baader RGB and IR cut filters through a WO ZS66, guided with a WO ZS110, QHY5 and PHD on top of an EQ6 pro. Stacked in DSS and processed with Photoshop.

11880_normal.jpeg

(click to enlarge)

Tony..

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MartinB

MartinB

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You've got some great colour data there Tony. I think it's ok binning the colour with the ZS66. Your colour image will look very uninspiring but the luminence sorts that out. The hardest thing can be matching the bloated stars in the RGB with the much smaller stars in the Ha luminence. You can afford to make good use of the minimum filter on the RGB.

The detail in the neb is fantastic, high quality luminence and the colour really enhances it. Really good work.

The stars are a bit green but that can be easily sorted.

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Whippy

Whippy

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Thanks all :). One good thing about posting up your 'finished' effort is that someone with fresh eyes can spot something that you might not have noticed, such as the Green stars for example. I've had a play but haven't managed to eradicate them. Anyone got any ideas?

Tony..

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MartinB

MartinB

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I had a look at your image Tony and started by lowering the black point in each channel a little. Then tried something very simple in PS. Using the colour select tool I clicked on the outer area of a green star then adjusted the slider to around 10 which picked out the green stars. I expanded by 5 and feathered 3. Then moved that selection into a new layer - layers/new/layer via copy. I then tweaked with the colour balance - dropped the green and boosted the yellow a little.

Usually when you do this the stars over the nebula look horrible but by picking out the green stars it worked ok. If you do have any dodgy looking stars you can always get rid of them using a layer mask (layers/layer mask/reveal all - select the brush tool and make sure the foreground colour is black then just dab over the stars you don't want).

Looked great on my screen after this but I've not posted it since posting a jpeg of a jpeg always seems to downgrade things too much.

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Whippy

Whippy

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Martin, I did try your suggestion and got completely lost (one of my new years resolutions is to get more proficient at PS) so I kind of cheated and selected the brighter stars with Noel's action and just de-saturated them. Not the most subtle of way of doing it, but they look a little better. Plus worked on the background a little more, probably overcooked it a touch but I think the overall effect is a little more pleasing.

11911_normal.jpeg

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Tony..

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Whippy

Whippy

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Honestly Martin it's nothing to do with your instructions, it's me. For some reason Photoshop remains something of a 'black art' program probably because I knew nothing about photography prior to starting imaging so all I know is what I've learnt in the last year or so. Cubase on the other hand...

Tony..

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Psychobilly

Psychobilly

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just fiddle with things till it looks right to you... provided you save at key stages then you havent got anything to loose and can always go back...

Ok this way its an art rather than a science but....................

If you monitor setup is out then your going to be piddling in the wind.... might look good to you but not the same to everyone else...

Billy.....

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Whippy

Whippy

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That's pretty much what I do Billy, I've got a fairly starightforward sequence to get to a certain point, then it's just making tweaks until I'm happy. I'm fairly comfortable with the basics, it's just the more advanced stuff I need to get to grips with. Like I say though, it's not even been a year since I started using Photoshop so I figure I'm doing alright so far. I spent best part of 10 years sequencing with Cubase and was only fairly proficient with it so I guess this may well take some time...

Tony..

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MartinB

MartinB

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Tony uploaded his files to UKAstronomers and I had a crack at processing. Did the align and combines of individual channels in Maxim. Combined the RGB in PS. Processed the luminence and RGB then created the LRGB. Converted the Ha to red and then added using colour as the blend mode using a layer mask to adjust. Did quite a lot of work on the star colour in the RGB

11930_normal.jpeg

(click to enlarge)

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